Feedback active noise control based on a digital signal processor for reducing noise from a blower machine

Abstract

Rotary blowers often produce high levels of sound at discrete frequencies, related to their rotational speed. High levels of sound can cause more or less severe damage to the ear, depending on its level and the time of exposure. In some cases it is mandatory to use hearing protection and reduce the time of exposure to noise. In other cases the noise affects the comfort of the workers and their productivity. Therefore, there must be applied elements and techniques to reduce noise, which complement the protection elements. If the noise frequencies are at the low end of the spectrum they may be difficult to attenuate by mean of passive techniques. In the present work it is presented the development of an active noise control system to cancel or reduce the noise emitted by a high power blower in a petrochemical plant. The solution is implemented on a digital signal processor and based on feedback scheme.